Method of producing a self-gripping fastening filament

ABSTRACT

A method is provided to produce a self-gripping fastener device which is integrally made as part of a thread or filament. A sheet of plastic is extruded having the profile of a series of hooks extending therefrom spatially staggered along the length of the sheet. The sheet is then cut into thin sections to form threads or filaments. The device is then employed either as a filament or as a yarn to form a fabric, felted surface or the like, the latter being releasably self-adhering by the application of pressure therein.

April 11, G, B U UK METHOD OF PRODUCING A SELF-GRIFFING FASTENING FILAMENT Original Filed March 6, 1968 2 g F/GZ Em F764 0 ATTORNEY Patented Apr. 11, 1972 3,655,855 METHOD OF PRODUCING A SELF-GRIPPING FASTENING FILAMENT George C. Brumlik, 154 Upper Mountain Ave., Montclair, NJ. 07042 Original application Mar. 6, 1968, Ser. No. 710,972, now Patent No. 3,522,637, dated Aug. 4, 1970. Divided and this application May 8, 1970, Ser. No. 35,817

Int. Cl. 132% 7/18 US. Cl. 264--147 Claims ABSTRACT on THE DISCLOSURE A method is provided to produce a self-gripping fastener device which device is integrally made as part of a thread or filament. A sheet of plastic is extruded having the profile of a series of hooks extending therefrom spatially staggered along the length of the sheet. The sheet is then cut into thin sections to form threads or filaments. The device is then employed either as a filament or as a yarn to form a fabric, felted surface or the like, the latter being releasably self-adhering by the application of pressure therein.

This application is a division of my previously filed application Ser. No. 710,972, filed Mar. 6, 1968 and entitled Self Gripping Fastening Filaments, now U.S. Pat. No. 3,522,637, issued Aug. 4, 1970.

The present invention relates to a method of producing fastening devices and in particular to a novel and improved fastening filament which is operatively to releasably grip an opposing fabric or other article in a selfadhering action.

Various self gripping fasteners, particularly suitable for releasably fastening fabrics and the like are presently available. Typical of such fasteners is a self gripping fastener assembly presently marketed under trademark Velcro which is in the form of pairs of fabric strips which are suitably secured to the opposing fabrics to be fastened together. The Velcro fastener comprises multiple rows of small vertically extending open plastic loops secured to the outer surface of one of the matching strips while matching small plastic hooks are secured to the outer surface of the opposite strips. Thus, when the two opposing strips are press-contacted the hooks link with the opposing loops in an interlocking action, and when pulled apart with suflicient force, the hooks disengage from their corresponding loops.

While the Velcro fastener provides an effective gripping action, the cost of manufacture thereof is relatively expensive. Furthermore, the Velcro type grip inherently requires that both of the opposing surfaces be provided with matching strips in order to effect an interlocking grip.

It is, therefore, an object of the present invention to provide a method of producing a fastener device in which the device is integrally made as a part of a thread or filament which is then employed either 'in filament form or in yarn form to form a fabric, felted surface or the like, the latter being self-adhering. The method is relatively inexpensive and simple.

Another object of the present invention is to provide a method of producing a fastening device of the character described in which fabric or felted surfaces formed by the device may be attached to opposed surfaces by the simple application of pressure thereon and may be released by pulling the surfaces apart with sufiicient force.

A further object of the invention is the provision of a method to produce filaments with self-contained fastening means, the fastening means being so constructed and arranged that they are initially retracted so that the filament may be handled in the normal manner and spun into yarn or otherwise employed for forming fabric or felted surfaces. The fastening means may then be treated to open up, forming a self-adhering surface.

In accordance with the principles of the present invention there is provided a method of producing a self gripping fastening filament for releasably gripping an opposing article. The fastening filament is made of flexible material and comprises an elongated body having a series of sharp-edged hooks, each extending from the elongated body; with the filament hooks being spatially staggered along the length of the filament body. The filament hooks when pressed against an opposing penetrable surface of the article is operative to penetrate and lodge in said article to thereby grip the article in a self-adhering action.

Additional objects and advantages of the invention will become apparent during the course of the following specifications when taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a sheet of extruded plastic having a suitable profile for forming a plurality of filaments which include integral fastening elements of a releasable fastener type in one embodiment of the present invention;

FIG. 2 is an elevational view of a filament having a plurality of integral releasable type of fastening elements, the filament being formed by chopping or cutting through the profile of the extruded sheet of FIG. 1, and then being treated to cause the filament hooks to partially open;

FIG. 3 is an enlarged elevational View of a length of yarn formed by spinning a plurality of filaments of the type shown in FIG. 2, the filament hooks being shown in closed condition;

FIG. 3A is an enlarged elevational view of a length of yarn similar to FIG. 3, but showing the yarn after treatment to cause the filament hooks to open;

FIG. 4 is a plan view of a piece of fabric formed by weaving a plurality of the yarns shown in FIG. 3, and then treating the fabric to cause the filament hooks to partially open;

FIG. 5 is a plan view of a piece of felted fabric or surface formed by felting the yarns of FIG. 3 and then treating them to cause the filament hooks to partially open;

FIG. 6 is an elevational view, on an enlarged scale, of a modified form of fastening element filament which may be formed by chopping or cutting through the profile of an extruded sheet;

FIG. 7 is an elevational view of the filament of FIG. 6 after having been treated to cause the stem portions thereof to be rendered erect and the hooks extending therefrom to open;

FIG. 8 is an elevational view, on an enlarged scale, of another modified embodiment of fastening element filament which may be formed by chopping or cutting an extruded sheet having a corresponding profile; and

FIG. 9 is an elevational view of the filament of FIG. 8 after having been treated to cause the filament hooks to open.

Referring in detail to the drawings, there is shown in FIG. 1 a sheet of plastic 10 which is extruded in the profile shown with a pair of series of spaced flutes 12 and 14 each having a truncated and relatively sharp edge 24 extending above and below sheet 10'. As shown in FIG. 1, in a preferred form, the upper series of flutes 12 is spatially staggered with respect to the lower series of flutes 14, across the width of sheet 10.

Fastening elements in accordance with the principles of the present invention may be formed by chopping or cutting through a profiled sheet, such as sheet 10', for example, in very thin sections as indicated by the cut lines 16, to produce fastening element filaments exemplified by filament 18 shown in FIG. 2. As shown in FIG. 2, filament 18 is initially formed with the profile of extruded sheet 10, with an elongated body 20 preferably having a width approximately equal to the thickness of sheet 10, and a series of inwardly curved hooks 22 corresponding to flutes 12 and 14. These hooks 22 may be transformed from their closed condition as shown by the profile of sheet in FIG. 1 to the partially open condition as shown in FIG. 2 when subjected to heat, mechanical, or chemical treatment. The degree to which the hooks are opened may be varied by selective control of the heat, mechanical, or chemical treatment to which the hooks are subjected. It is understood that filament 18 is of the usual filament-like thickness, so that stems 20 as well as opened hooks 22 are relatively flexible, whereby a plurality of filaments 18 may be easily spun together to form a yarn to be subsequently interwoven, or felted together as hereinafter described.

With the hooks 22 in closed condition, the filaments 18 may be spun together to form a yarn 26 (FIG. 3) which may thereafter be subjected to heat mechanical or chemical treatment to cause hooks 22 to open, as shown in FIG. 3A. The yarn 26 may serve various purposes. For example, a single length of the yarn may be woven into regular fabric and its hooks opened to provide a zipper-type closure line in the fabric. In addition, a plurality of yarns 26 having open hooks 22, may be matted together in'a felting operation to form a felt fabric 28 having extending hooks 22, as shown in FIG. 5, in one embodiment of the present invention. In the felting operation when yarns 26 are pressed together, the flexible hooks 22 engage contiguous yarns to form a skeined array of interlocking yarns as shown in FIG. 5.

In another embodiment of the present invention a plurality of filaments 18 with opened hooks 22 may be matted together in a felting operation causing hooks 22 to engage the bodies 20 of contiguous filaments to form a skeined array of interlocking filaments 18 (not shown) somewhat similar to the skeined array of interlocking yarns shown in FIG. 5. It is also possible to arrange a plurality of yarns or filaments with closed hooks loosely in a skeined array and then to treat them so that the hooks open up and interlock to provide a felted surface.

In yet another embodiment of the present invention, a plurality of yarns 26 with hooks 22 in the closed condition, are interwoven to form a fabric, and the fabric is then subjected to heat or chemical treatment to cause hooks 22 to open or partially open, resulting in a woven fabric 30, as shown in FIG. 4.

The resulting fastening fabric formed by felting individual filaments 18 (not shown), by felting yarns 26 as shown in FIG. 5, or by weaving yarns 26 as shown in FIG. 4 may be suitably secured such as by stitching, by its own self-gripping action, or by means of adhesive to one of the article surfaces to be releasably fastened. A particular advantage of the invention is that if the article is of soft or frangible nature, the fastening fabric or single strand of yarn can be attached thereto by its selfadhering action without requiring additional fastening means. If the opposed material to be releasably fastened is made of a fibrous material such as suede, plastic, foam, felt, -etc., the fastening fabric of the present invention will grip the opposing material when the opposing materials are pressed together with sufiicient pressure to cause the exposed hooks 22 to engage opposing fibers of the material to be fastened. If the articles to be releasably fastened are smooth or impenetrable by the fastening elements, than the fastening fabric of the present invention may be suitably secured to the opposing article surfaces, and when pressed together, the hooks 22 will engage opposing fastening fabric yarns 26 or filament stems 20 as the case may be, in addition to engaging opposing books 22.

The further embodiments of the present invention as shown in FIGS. 69, are illustrated by way of example to demonstrate that the filaments for forming the fastening fabric of the present invention may have extending books of various shapes.

In the embodiment of the present invention shown in FIG. 6, filaments 32 may be formed by chopping or cutting through an extruded sheet of plastic (not shown) having a profile or cross-section corresponding to the shape of filament 32, in a manner similar to that described above with respect to FIGS. 1 and 2. Filament 32 comprises an elongated body 34, having sharp edged hooks 36 extending from opposite sides thereof in staggered configuration at spaced intervals along the length of body 34. Each of the hooks 36 has at least one pair of sharp-edged curved barbs 38 extending in opposite directions from the stem portion 40 of hook 36, with the pointed tip 42 of each barb 38 being curved inwardly toward stem portion 40.

As described above with respect to filaments 18 of FIG. 2, filaments 32 may be subjected to heat, mechanical or chemical treatment to cause books 36 and barbs 38 extending therefrom to open to the erect condition as shown in FIG. 7. Filaments 32 in the erect condition shown in FIG. 7 are particularly suitable to be felted together in a manner similar to that described above with respect to filaments 18, to produce a felt fastening fabric somewhat similar in overall appearance to the felt fabric 28 of FIG. 5.

In other applications, filaments 32 in the closed condition of FIG. -6 may be spun together to form yarns which may be interwoven and subsequently subjected to heat or chemical treatment to cause hooks 36 and barbs 38 to open, in a manner similar to that described with respect to FIGS, 3 and 4. Similarly, filament 32 or yarns formed thereof, may be treated to open hooks 36 and barbs 38 and then felted in the manner previously described to form a fastening fabric somewhat similar to that of FIG. 5.

In the embodiment depicted in FIG. 8, filaments exemplified by filament 44 may be formed by chopping or cutting through an extruded sheet of plastic (not shown) having a profile corresponding to the shape of filament 44, in a manner similar to that described above.

Filament 44 comprises an elongated body portion 46 having pairs of sharp-edged books 48 extending from opposite sides of stem 46, with the pointed tip 50 of each hook 48 being curved inwardly toward stem 46.

In a manner similar to that described above with respect to filaments 18 and 32, filaments 44 may be subjected to heat or chemical treatment to cause hooks 48 to open to the erect conditions shown in FIG. 9, wherein filaments 44 are particularly suitable to be felted together to form a felt fastening fabric somewhat similar to that of FIG. 5. Again, in another embodiment, filtments 44 with hooks 48 in the closed condition of FIG. 8, may be spun to form yarns similar to that shown in FIG. 3, which yarns may subsequently be interwoven and subjected to heat, mechanical or chemical treatment to cause hooks 48 to open, or the yarns may be treated to cause hooks 48 to open with filaments 44 then being felted in the manner of FIG. 5 to form a fastening fabric.

While preferred embodiments of the invention have been shown and described herein, it is obvious that at numerous omissions, changes and additions may be made in such embodiments without departing from the spirit and scope of the invention.

What is claimed is:

1. A method of making self-gripping fastening filaments for releasably gripping an opposing article comprising the steps of extruding a sheet of plastic material with a cross-sectional profile in the form of an elongated body having a series of spatially staggered curved flutes terminating in points and extending laterally along the length of said body from both sides thereof, and thereafter cutting said sheet by a series of closely-spaced cuts in a direction parallel to said profile, to form a plurality of said fastening filaments having an elongated body and a series of spatially staggered curve hooks terminating in points.

2. A method as defined in claim 1 in which the profile of said sheet is formed to provide a series of spaced tightly curled flutes extending from said body and directed inwardly thereto to form tightly curled hooks in the cut filaments, said method including the additional step of treating said tightly curled hooks of each of the cut filaments to cause said hooks to open suificiently to expose the pointed ends thereof.

3. A method as defined in claim 1 in which the profile of said sheet of plastic material is formed to provide a series of spaced tightly curled flutes extending from said filament body and directed inwardly thereto to form tightly curled hooks in the cut filaments, said method including the additional steps of spinning a plurality of said cut filaments together to form a yarn with said curled hooks projecting therefrom, and thereafter treating said projecting curled hooks of said yarn to cause the hooks to project sufficiently to expose the pointed ends thereof.

4. A method as defined in claim 1 in which the profile of said sheet of plastic material is formed to provide'a series of spaced tightly curled flutes extending from said filament body and directed inwardly thereto to form tightly curled hooks in the cut filaments, said method including the additional steps of spinning a plurality of said out filaments together to form a yarn, weaving said yarn to form a fabric having said curled hooks projecting therefrom, and thereafter treating said projecting curled hooks of said fabric to cause the hooks to project sufficiently to expose the pointed ends thereof.

5. A method as defined in claim 1 in which the profile of said sheet of plastic material is formed to provide a series of spaced tightly curled flutes extending from said filament body and directed inwardly thereto to form tightly curled hooks in the cut filaments, said method including the additional steps of spinning a plurality of said cut filaments together to form a yarn, matting said yarn to form a felt having said curled hooks projecting therefrom, and thereafter treating said projecting curled hooks of said felt to cause the hooks to project sufficiently to expose the pointed ends thereof.

References Cited UNITED STATES PATENTS 3,515,778 6/1970 Fields et al. 264147 2,464,746 3/1949 -Gering 264-177 F 2,750,631 6/1956 Johnson 264-177 F 3,161,708 12/1964 Scragg 264177 F 3,330,187 7/1967 Kohler et al. a 264-177 F 3,470,685 10/1969 Hall et al. 264-177 F 3,503,199 3/1970 DufOrt 161-175 JAY H. WOO, Primary Examiner US. Cl. X.R. 

